Wireless receiving tuner



Jam 5 9 19260 E. P. ROOM/AN WIRELESS RECEIVING TUNER 1, 1922 2 Sheets-Sheet 1 Filed Feb.

' INVENTOR ATTORNEY Patented Jan. 5, 1926.

UNITED STATES ISAAC I. RODM AN, F NEWARK, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO GAROD COREORATION, 0F IBELLEVILLE, NEW ERSEY, A CORPORATION OF NEW JERSEY.

WIRELESS RECEIVING TUNER.

in thecounty of Essex and State of New Jersey, have invented a new and useful ""Wireless Receiving Tuner, of which the following is a specification.

My invention relates to improvements in wireless receivers, in which a crystal detector adjusted by 0 of two helical coils, and the ob ects of my and condenser connected in series are conductively coupled to .the primary circuit and in which the primary circuit inductance 1s varying the relative positions improvements are firstto provide a compact, pocket size, wireless tuner, and secondto aiford facilities for adjusting the values of inductance.

I attain these objects by the apparatus illustrated in the accompanying drawings in Figure 1 is a perspective view, the box being open and partsbeing broken awgy. e

Fig. 2 is a bottom plan view of a move I inductance member.

, Fig. 3 is an end view of the member of Fi 2 Fig.- 4 is a plan view, on a reduced scale,

of a part of the device, showinglthe fixed cooperating inductance member.

Fig. 5 is an endview of the part shown .in Fig. 4, and e Fig. 6 is a diagram'of the wiring of the j instrument.

Similar reference characters refer to similar parts throughout the several views.

The circuits of my receiver'are mounted upon and in a small compact box, which is of ocket'size, the dimensions being of an or er to fitin' an ordinary pocket, and which comprises two parts, A and B, connected by the metal hinges E, F, one part A being the box' proper andthe other part B being the cover. The parts may be closed and secured together by means of a hook N adapted to engage a pin or screw 0.

The receiver, such as I have herein dis closed to illustrate an embodiment of my invention, usually comprises, an inductance, condenser, detector and the connected circuits adapted to efliciently receive and make audible the electro-magnetic impulses received. My invention includes the arrangement of these devices within the casing or box and with reference to each other, so that the whole device is compact, will be easy to operate, and may be completely enclosed when not in use.

For this purpose I mount a portion of the electrical devices of the circuit on one part of the box and the remainder of the electrical devices on the other part. It is immaterial in which part any particular device is located. All that is necessary is that the several devices be so arranged on their respective parts that they do not interfere with each other to prevent the closing of thebox.

To illustrate one'embodiment of the in- .vention in the accompanying drawings I show aninductance D G mounted on one part, as here illustrated. in the part A or box proper, and the condenser P and detector Q mounted on the other part or upon the inner side of the cover.

The inductance members or devices D G are mounted to slide rectilinearly relatively to each other on the part A. Each inductance member comprises a flat helical or spiral coil of insulated wire in which the successive convolutions are very {close toether. The coil D is mounted u on the bottom of part A near one end, an' can be secured thereto in any suitable manner, as

by a suitable adhesive or glue. The coil G is in like manner secured to one side of a blocklike mounting O in such position there- 'on that the center of the coil coincides with the point of intersection of the diagonal lines drawn from the corners of the block G. The part of the box on which the inductances are mounted are provided with arallel guideways U V which are illustra in this embodiment of the invention as formed in the side pieces H and I of the box A, one end of the box A being open or unobstructed to allow the insertion and removal of the coil G and its mounting G into and out of the guideways or grooves U V. This arrangement provides means for variably sliding one coil member over the other to vary the inductance of the .circuit and hence the wave length adjustment, the coil G facing the coil D and being fairly close thereto to secure close coupling and to permit the use of a very small box. The mountin C has secured to it upon opposite sides side contacts L M, consisting of springy strips of metal, the contact L being electrically con-1 I nected by a conductor 6 to the outside of the movable coil G and the fixed parts of the receiving circuit. The coil D is so mounted, that, when the mounting C is flush with the open end of the side pieces H I, the coils will be in maximum overlapping position with their centers coinciding. The condenserP and detector Q, are secured to the part B, upon its inner surface but at the end thereof remote from the inductance D- (and also mounting G, if the latter is at the right as shown in Fig. 1), so that when the parts A and B are closed the electrical devices will not interfere but will occupy different portions of the box, thereby providing a compact and completely enclosed unit, the cover B being provided with a vertical strip at its right hand and (Fig. 1) adapted to cooperate with strips or sides H I to complete the enclosure and cover the open end of box A.

Any type of suitable detector may be employed in this invention, such for instance as a crystal. specific form of crystal detector Q which is especially adapted for a portable pocket set of the present character and which is reasonably immune to shocks, blows or vibrations. This detector comprises a crystal of any suitable character now well known, suitably mounted, as for instance in a metal and a flexible wire R in the circuit of the receiver, secured at one end by a screw S and having a free end which can be moved to engage the surface of the crystal at different points to find a sensitive place, the wire by reason of its flexibility and springiness allowing this adjustment and providing a firm pressure on the crystal. The wire R is pref erably of bare soft drawn copper having a diameter not exceeding 3/64 inches inertia, the wire when once located in position and isnot susceptible to shoe... blows, etc.

Spring clip terminals or binding posts T T, T and T are secured to the inner side of the cover B in such position as not to interfere with the closing thereof. The minal T is for the antenna lead, the terminal T for the ground lead and the iniials T and T for the phone or amplifier ea s.

I have however illustrated a" of inductance coil D through conductor 2,

mounted on part B, hinge E and conductor 3, mounted on part A, the oposite end of coil D being electrically connected to strip K by'conductor 4. The other strip J is electrically connected to hinge F by conductor 7 mounted on box A and hinge F is electrically connected to ground terminal T through conductor 8. The wire R is electrically connected by a conductor 9 to one terminal ofthe condenser P, this terminal of the condenser being electrically connected to the telephone clip T by a lead 10 and the opposite terminal of the condenser being electrically conected to the other phone clip T by a lead 11. The circuit through coils D and G may be traced from hinge E, through coil D to strip K, from'strip K and contact M through coil G to contact L and strip J and from there to hinge F. By reason of the construction and connections above described the flow of current through the coils is in opposite directions (although they may be in the same direction) and hence (when connected as shown) they inductively oppose each other, like a variometer, the circuit having minimum inductance when the coils are m maximum overlapping position and maximum inductance when the coil Gr is at the extreme left (Fig. 1), thereby varying the wave length adjustment from minimum to maximum.

iou

The circuits are also illustrated in Fig. 6

. and form what are known in the art as the primary and secondary circuits. The primary circuit includes the inductance D G and the secondary circuit includes the de-' .tector Q, condenser P, if used, a d. t l

phones. I 'By removing mounting C and reversing its position so that contact M engages strip J and contact L engages strip K, the direction of flow of current is reversed in coil G so that the inductances of the circular or pancake coils add as they approach each other thereby securing an increased range of wave length adjustments instrument and other coil mountings apnine of inductance different from eac other ied, which other coil mountings ma have Coil mounting C may be removed from the I 12c ,nalring it ossible for the instrument tohave 7 V pariable inductance values over a wide range.

I is possible by providing additional grooves U and V and additional coil mountings O to apply an inductive variable coupling betweeri the primaryand secondary circuits.

I claim: 1 1. A device xof thecharacter described comprising a support having an extended surface, flat 'coils thereon relatively movable laterally over the faces of each other into and out of overlapping relation and having areas compared to that of said supporting surface such as to maintain said coils in parallelism in each position without projecting beyond the edges of said support, means asso'ciated with said coils to maintain an electrical connection a between the same in the different relative positions thereof, and a member associated with said support and adapted to enclose said coils; said support and said member constituting an enclosure serving, when in closed relation, to maintain said coils within the confines of said edges and prevent the removal thereof.

2. A device of the character described comprising a support, a fiat coil mounted on said support at one end thereof, parallel conducting and guiding members mounted on said support at opposite sides of said coil and extending beyond the same, a slidable supporting member, a flat coil thereon facing said first named coil, contacts carried by said supporting member and slidably engaging said conducting members; said contacts maintaining an electrical connection between said coils in-the different relative positions thereof, and a member associated with said support and adapted to enclose said coils and serving, when in closed position, to maintain 1 said COllS withln the confines of sald support and prevent the removal thereof.

3. A device of "the character described comprising a support having an extended surface, a plurality offlat coils thereon relatively movable laterally over the faces of each other intoand out of overlapping relation and having areas compared to that of said supporting surface such as to maintain said coils in parallelism in each position without projecting beyond the edges of said support; said coils being arranged to be either increasingly additive in their inductive effects or increasingly opposing in their inductive effects, as desired, upon relative movement thereof, and a member associated with said support and adapted to enclose said coils and serving, when in closed position, to maintain said coils within the confines of said support and prevent the removal thereof.-

4. A device of the character described comprising a support, a flat coil thereon at one end thereof, parallel guiding and conducting members mounted on said support at opposite sides of said coil and extendmg beyond the same towards the opposite end of said support, a slidable supporting block, a flat coil upon the side thereof facing said first named coil, spring contacts on said.- block slidably engaging said conducting by said support or enclosing said coils and 7 serving, when in closed position, to maintain said coils within the confines of said support and prevent the removal thereof.

ISAAC P. RODMAN; 

